This invention relates to devices that absorb the energy of an impact. More particularly, this invention relates to devices used to provide protection to joints and other areas of articulation. Still more particularly, this invention relates to devices that provide protection to joints and other areas of articulation and allow air and moisture to pass through the protection to provide breathable protection to a user that allows evacuation of perspiration.
Many sports and occupations require safety equipment such as padding that protects the users from impacts that occur. Some non-limitative examples of sports where padding is needed include bicycling, football, hockey, in-line skating, skiing and snowboarding. A non-limitative example of an occupation that requires safety equipment is construction. Designers of such safety equipment face a number of obstacles.
One area of particular concern to designers of safety equipment is padding. Of particular concern to the designers is padding for areas of articulation. An area of articulation is a joint or other area in which at least two adjacent body parts move in different directions during an activity. For example, one common joint to protect is the knee which must bend when a user is in-line skating, running, or walking. Users prefer padding that allows a full range of motion with minimal discomfort. Users also prefer padding that allows for the evacuation of perspiration, which is known as breathing in the art. Other concerns include that the padding is washable, lightweight and durable.
Prior art padding designs do not adequately meet these needs. One type of pad, such as the pad disclosed in U.S. Pat. No. 6,029,273 issued to McCrane, has a hard outer casing. This type of pad does not allow perspiration to escape. Therefore, this type of pad is not ideal for use in clothing. Further, this type of pad restricts movement, as the outer casing is rigid and inflexible. To allow articulation, some pads with rigid casings do provide articulated plates. Articulated cases include a plurality of plates fitted together that allow the plates to move with respect to one another in order to facilitate movement. These casings may solve the mobility problem. However, the casings with articulated plates still do not allow perspiration to escape, are heavy, bulky, and are still too rigid to insert into clothing. Furthermore, the cost of making the articulated plates is expensive and time consuming.
A second type of casing includes flexible, outer casings of porous, breathable inelastic material overfilled with resilient discrete beads of elastic material. An example of this type of pad is disclosed in U.S. Pat. No. 5,920,915 issued to Bainbridge et al. This material, while breathable, still impedes movement because the overfilled pads are semi-rigid. Therefore, this type is unacceptable for padding an articulated area.
A third type of pad is a foam pad that has score lines cut into the pad to facilitate movement. An example of this type of pad is disclosed in U.S. Pat. No. 6,093,468 issued to Tums et al. Score lines are indentations cut into the material. The cuts allow the foam of the pad to flex to allow the pad to flex. The foam material is breathable and allows perspiration to escape. The score lines improve the flexibility of a pad. However, the range of motion is still impeded as the score lines do not allow the pad to twist or form completely to an area due to the excess material.
It is, therefore, the desire of those skilled in the art to provide a pad that allows perspiration to escape and has a desired flexibility.
The above and other problems are solved and an advance in the art is made by a protective pad made in accordance with this invention. A first advantage of a protective pad made in accordance with this invention is that the pad is breathable, meaning that perspiration is allowed to escape. Furthermore, the pad is washable as part of a garment. A second advantage of this invention is that the pad is flexible and may move with an area of articulation to allow a user a full range of motion with minimal discomfort.
In accordance with this invention, an energy absorbing protective pad has a pad of energy absorbing material. The pad has score lines along a first axis and a second axis. The score lines are cut into the pad to provide articulation. Along the second axis, the pad has cuts at the periphery of the pad. The cuts provide flexibility to the pad.
The energy absorbing material may be a foam or any other semi-rigid material. The foam may be single layered or multi-layered. Preferably, the energy absorbing material is a bi-density foam. The bi-density foam has a first layer on a bottom side of the pad having a first density and a second layer on a top side of the pad having a second density that is a higher density than the first density. The score lines are cut through the second layer of foam and through a substantial portion of the first layer. Preferably, the score lines are cut through three-quarters of the pad. However, the score lines may also be cut to any other depth including, but not limited to, one-half and one-quarter through the pad.
The inner side of the pad may be affixed to a piece of stretch or non-stretch fabric. The pad may be sewn or glued to the fabric. A piece of outer fabric may be affixed to the piece of stretch fabric around a perimeter of the pad to enclose the pad. The pad is not affixed to the outer fabric to add flexibility. When the pad is affixed to the stretch fabric, the score lines may completely sever the pad into a plurality of individual members.
The score lines may be cut into the pad in the following manner. A first plurality of score lines are cut into the pad substantially along a first axis. The first axis is substantially longitudinal with reference to the area of articulation being protected. For example, in a knee pad, the first axis would be substantially parallel to the leg. A second plurality of score lines are cut substantially along a second axis. The second axis is substantially perpendicular to the first axis. The first and second plurality of score lines define a plurality of polygons on the pad. The polygons are preferably narrower along the first axis than the second axis to promote flexibility along the first axis.
In a preferred embodiment, the cuts along the periphery of pad along second axis promote flexibility. The Cuts completely sever members at the periphery of the pad along the second axis to allow flexing of the pad. Polygons defined by cuts have reduced dimensions in the direction of the first axis to further promote flexibility and shaping of the pad to the member protected by the pad. The cuts also eliminate excess material in the direction of the first axis. The excess material is removed because this excess material impedes flexing of the pad in the direction of the first axis.
The pad may be molded to have a curvature traversing the second axis. A concave side of the pad is fitted to the area of articulation being protected. In a preferred embodiment, the energy absorbing material of the pad is heat moldable and heat is applied to the pad to form the curvature.
The protective pad may then be inserted in pockets or enclosures in a garment to form any number of pads. For example, a protective pad in accordance with this invention may be incorporated into a knee pad, a hip pad, a shoulder pad, or an elbow pad.